Depressed adjuvant arthritis in rats transferred with spleen cells from Trypanosoma cruzi-infected syngeneic donors

ABSTRACT

In the present we investigated whether the attenuating effect of chronica Trypanosoma cruzi (Tc) infection on adjuvant arthritis (AA) in the rat could be transferred to naive recipients. Transfer of whole spleen cells, but not of serum, from Tc-infected rats reduced AA (x ñ SEM 11 ñ 0.5) in recipient animals (control values, x ñ SEM 19 ñ 0.7). Transfer of a T-cell enriched subpopulation from spleen cells of Tc-infected rats (obtained by filtration through a nylon column) resulted in a similar attenuationb of AA (x ñ SEM 7.5 ñ 2.2). The arthritic response of rats intraperitoneally inoculated with 2 x 10**5 Tc 48h before induction did not differ from that observed in controls. Neither parasites nor specific antibodies were observed in suckling mice inoculated with serum or cell suspensions employed in transfer experiments. Consequently, the depressive effect on AA could not be directly attributed to Tc per se. We hypothesize that a homeostatic immunosuppressor mechanism may be responsible for this phenomenon